Compressor, particularly for refrigerators



March 26, 1940. e. THOMAS r 2,194,726

COllPRESSOR, PARTICULARLY FOR REFRIGERATORS Filed June 22, 1936 2 Sheets-Sheet 1' Inventor:

G. THOMAS March 26, 1940. 2,194,726

COMPRESSOR, PARTICULARLY FOR asraresanons 2 Sheets-Sheet 2 Filed June 22, 1936 I n ventor Refrigerators,

Patented Mar. 26, 1940 PATENT OFFICE pomnnsson, PARTICULARLY FOR REFRIGERATORS Gustav Thomas, Dresden, Germany Application June 22, 1936, Serial No. 86,690

In Germany June 21, 1935 7 Claims.

(Grantedunder the provisions of sec. 14, act of March 2, 1927; 357 0. G.

The present invention relates to a refrigerator. More particularly it concerns a refrigerator of the compressor type in which a cooling medium, for instance sulfurous acid, is withdrawn in a 5 gaseous state by a compressor or pump from a vaporizer and pressed into a condenser where it is liquefied; then it is reintroduced into the vaporizer by way of an accumulator. The compressor or pump should be of the positive acting type,

in which, for instance, a piston is reciprocated in a cylinder.

According to this invention the working chamber, e. g. the cylinder of the pump, is covered by a member which forms the bottom of an accumulator or collecting chamber and is equipped with a valve predeterminedly connecting said working and collecting chambers.

the mechanical compression type, have heretofore been very complicated and their manufacture was expensive. Nevertheless the compression refrigerator systems hitherto known are not satisfactory in operation because of frequent and undue losses of cooling medium, oil, or both, and of disturbances created thereby.

The principal object of the present invention is to provide a refrigerator which is of simple construction and which does not have the disadvantages just mentioned above.

In this invention plate valves are used. From the rim of such a valve depend a skirt or lugs adapted to be received by a guide groove sur-- rounding .the valve opening.- The valves are held in a closed position by means of suitable springs. The production of these valves is most economical, they are readily installed and easily controlled in operation. In spite of their simple construction the valves are, however, very reliable in performance.

The valves are advantageously closed by-means of flat springs which allow choice concerning. length, thickness and width. A single spring maybe used for the control of a plurality of valves.

" In order to obtain atight seal between a pump or compressor and a tube to be connected thereto a perforated double cone may be used, which fits upon one side .into a correspondingly counter sunk part of the pump and upon the other side into the end' of the connecting tube which is 50 'flared to suit. The tube and cone are pressed onto the part by means of screws or by means of a threaded sleeve.

The bore in the pump cylinder, through which passes the pump shaft, is equipped with a stuff- 55 mg box in the form of collapsible and expansivalves arranged thereon. a

F 3 view.

Fig. 4 is an exploded perspective view of a piston illustrating the plate valve arrangement.

Fig. 5 shows the upper part of the pump cylinder casing seen from the rear.

Fig. 6 is a corresponding fragmentary crosssectioned side view showing the connection beis a corresponding cross-sectioned side tween the pump cylinder and the inlet tube in 20 exploded detail.

The manner of operation of the cooling plant is similar to the known cycle of compressor type refrigerators: I

The pump A gasi'fies the cooling medium contained in the vaporizer C which draws it through the tube B and forces it through the pipe D into the condenser E, which is equipped with afan F. From the condenser the cooling medium flows back into the vaporizer C by way of an accumulator and through the tube G. The supply of cooling medium to the vaporizer C may be con trolled as customary by a float H.

The compressor or pump A has a casing I,

which comprises two working cylinders 2 accommodating the pistons 3. The open lower end of easing l is closed by means of a bottom plate not shown. The lower part of the casing contains bearings 25 and 26 for a crank shaft 4 which connects to the pistons '3 by means of the piston rods 40 E. A spring 38 presses the shaft 4 towards a ball bearing 29 formed in a screw plug 28 which is screwed into and closes the casing l. The screw plug 28 and the end 21 of shaft 4 are counter sunk in order to accommodate a ball 29 interposed to take up end thrust. At the other end of the casing, a stufiing box comprising the metal bellows 36 provides a seal for the opposite end of the shaft 4, so that no cooling medium can escape from the casing. a

The upper end of the casing is closed by means of a cover plate 6. This plate 6 forms the bottom of an accumulator or collecting chamber 1 Fig. 1. In axial alignment with the cylinders o the outer surface of the collar 3|.

the outlet openings 8 extend through the plate 6.

These openings are closed by plate valves:

. Figs. 2 and 3 show grooves 9 which extend in the plate 6 concentrically around the openings 8.

' .The openings 8 are covered by thin flat valve plates III. From the edges or rims of plates I0, depend the lugs or tongues II into the guide grooves 9 in the plate 6. The lugs or tongues I I are vertically slidable in the grooves 9 or may clear the walls of these grooves, serving however to retain the plates III in registering relationship upon openings 8. The members II] can therefore be lifted up from the upper surface of the plate 6 but are retained in vertical alignment as long as the lugs II extend into the grooves 9. The valve plates or bodies I are depressed onto their seats by flat springs I3, I3 which may diifer from each other in length, width and for a breathing of the valve bodies, so to speak,

whereby any noise which might be caused during operation is reduced and the bodies rapidly adapt themselves to their seats.

Similar valve bodies are used for closing the upper end of the hollow piston 3, piston rings providing an outer sliding seal between piston and cylinder bore, as usual. Each piston top shows a circular guide groove 9a which is adapted to receive the lugs I la of the valve body 3a. Each valve body is retained by means of a strip-shaped member or by means of a circular cover 3b which is affixed to the top of the piston, e. g., by small pins. This mounting again offers a slight vertical play for the valve body 3a which may breathe. the projections IIa remaining engaged in the groove 9a. The covers 3b have openings for the passage of gas and oil.

When the pump is working the plate valves III are alternatelylifted while the respective piston valves 3a are closed. During down strokes the positions of the valves are reversed. Thus the cooling medium flowing through the piston is forced into the collecting chamber I under pressure.

In order to allow for the play of the shaft 4 without risking leakage of the cooling medium from the casing I, the right bearing 26 is provided with concentric steps 32 and 33 (see Fig. 1) and the step 33 has an internal thread. Adjacent to a journaled section 33 the shaft 4 comprises a collar 3|. An annular groove 3Ia is formed in A metal packing 34, for instance a ring which is pressed by spring 38 into sealing the sliding abutment with 65. collar 3| and has an inner rim which projects into and engages similarly in the groove 3 la. Another metal packing 35, made for instance from copper or lead,'is pressed against the shoulder between the steps 32 and 33 as a seal for the large flange on bellows 36. Ring 34 connects tightly with the other end of the bellows 36. A sealing plug 31 engages the end of flange bellows 36 in hub 26, depressing said flange into packing ring 35. Plug 31 also offers a reaction for pressure spring 38. The spring 33 presses the inner packing ring 34 against the collar 3| of the shaft 4. Shaft 4 reacts in turn upon plug 28 by way of ball 29, as described before. Thus collar 3| is clear of the hub 26 and of easing I. Due to the rotation of the shaft the inner rim of the packing 34 will gradually enter the groove 3Ia and form an additional seal. Y

The ends of a filling tube I9 through which the cooling medium may be replenished and a tube 22 leading to the vaporiser are connected upon a hollow projection I4 of easing I (Figs. to 6). A baiile member 39 may be arranged where the cavity of this projection I4 merges with the interior of the casing I. The body I4, which may for instance be of rectangular shape has two tapped, countersunk openings I6. The thread serves to receive a threaded clamping collar, 20 on top, 24 at the bottom. In the interior of each opening I 0 a conical seat I5 is formed for a double cone I8 or 23 respectively. In the embodiment of the invention shown in Fig. 6 the tube I9 is coupled to the upper end and the tube 22 to the lower part of the body I4. The C0!- nection of the tube I9 is formed by pressing the flared end of the tube I9 against the double cone I8'and locking the tube I9 in this position by means of a clamping collar 20 having a conical recess at its inner end. The connection will center itself when the collar 20 is screwed into the passage opening. The other tube 22 is similarly connected by means of the double packing cone 23 and the recessed clamping collar 24.

After the cooling medium has been filled in, the upper end of the tube I9 is closed, for instance by squeezing it together or by soldering. The lower tube 22 leads to the vaporizer. In the embodiment shown, the cones are inclined at 45, but this angle of inclination may be of any other desired value.

I claim:

1. A compressor for refrigerators, comprising a pump casing, a plurality of pump cylinders arranged within said casing, hollow pump pistons slidably arranged in the cylinders, piston rods attached to the pistons, a drive shaft for reciprocating said pistons, a cover for said pump casing, a collecting chamber in said cover, valve seats in said cover and said pistons, means connecting the suction side of said pump with the source of a cooling medium and the pressure side thereof with a condenser, automatically controlled plateshaped, spindle-less valves for the supply of cooling mediumto the said collecting chamber, cooperating plate-shaped, spindle-less valves on the pistons, and guide means formed in and depending from the rims of said valves into clearances surrounding said valve seats.

2. A compressor, particularly for refrigerators, comprising a pump casing, a plurality of pump cylinders arranged within said casing, hollow pump pistons slidably arranged in the .cylinders, piston rods attached to the pistons, a drive shaft for reciprocating said pistons, a coverfor said pump casing, a collecting chamber in said cover, means connecting the suction side of said pump with a source of a cooling medium and the pressure side thereof with a condenser, automatically controlled plate-shaped, spindle-less valves for the supply of the cooling medium to the said co lecting chamber. and cooperating plateshaped, spindle-less valves in the piston bores, each of said valves comprising a substantially plate-shaped valve body, a seat for the same, proections on said valve body, a circular groove formed adjacent the said seat and being adapted to receive said projections, a spring arrangement "15 the cover and common holding means for said controlling the movements of the valve bodies in springs. 3. A compressor for refrigerators, comprising a pump casing, a plurality of pump cylinders arranged within said casing, hollow pump pistons slidably arranged in the cylinders, piston rods attached to the pistons, a drive shaft for reciproeating said pistons, a cover for said pump casing, a collecting chamber in said cover, means connecting the suction side of said pump with the source of a cooling medium and the pressure side thereof with a condenser, automatically controlled plate shaped, spindle-less valves for the supply of a cooling medium to the said collecting chamber, and cooperating plate-shaped,

spindle-less valves in the piston bores, each of casing, hollow pump pistons slidably arranged a in the cylinders, piston rods attached to the pis- "tons, a drive shaft for reciprocating said pistohs, a common cover for said casing and said cylinder, a collecting chamber in said cover, automatically controlled valves for thesupply of cooling medium to the condenser in the said cover, and cooperating valves on the pistons, each of said; valves comprising a substantially plate-shaped valve body, a seat for the same, projections on said valve body, a circular groove formed adjacent the said seat and being adapted to receive said projections, a spring arrangement controlling the movements of the valve bodies in the cover, common holding means for said springs, and means for controlling the move- I ments of the valve bodies on the pistons comprising strip-shaped bodies seated in a shoulder surrounding the valve seat.

' 5. A compressor, particularly for refrigerators, comprising a pump casing, a plurality of pump cylinders arranged within said casing, hollow pump pistons slidably arranged in the cylinders, piston rods attached to the pistons, adrive shaft for reciprocatingsaid pistons, gas-tight bearings for said drive shaft, a closure on one of the gastight bearings and comprising an anti-friction means serving as end thrust in one axial direction for said drive-shaft, a shoulder on said stream the otherbearing, a packing surrounding said shaft and sealing upon said shoulder, a second packing seated on said other bearing, a collapsible and expansible metal bellows seated upon said other bearing by way of the second, and relatively rotatably engaged upon said shoulder way of the first of said packings, ahelical' spring within said bellows for eflecting said relatively rotatable engagement against the reaction of said anti-friction means, and reaction and retaining means on said other bearingfor compressing said'spring and for engaging the bellows by way of the second one of the packings upon the said other bearing, a common cover for said pump casing and said cylinders, a collecting cover in said chamber, automatically controlled plate-shaped, spindle-less valves for the supply of cooling medium to said collecting chamber, and cooperating plate-shaped, spindleless valves on said pistons.

6. A compressor, particularly for refrigerators,

comprising a pump casing, a plurality of pump cylinders arranged within said casing, hollow pump pistons slidably arranged in the cylinders, piston rods attached to the pistons, a. drive shaft for reciprocating said pistons, a common cover for said pump case and said cylinders, a collecting chamber in said cover, automatically controlled solid disc shaped, spindle-less valves for the supply of cooling mediums to said collecting chamber, said valves being marginally bent down to engage in clearances surrounding the valve openings, similar spindle-less valves in the bores of said pistons, and means for controlling a the movements of said valves in the piston bores,

casing, a collecting chamber in said cover, means connecting the suction side of said pump with the source of a cooling medium and the pressure side of it with a condenser, automatically controlled plate shaped, spindle-less valves servicing for the supply of cooling medium to the said collecting chamber, and mounteduponw said cover and centrally upon said pistons, each of said valves comprising a substantially plateshaped valve body, a seat for the same,pro jections on said valve body, a circular groove formed adjacent the said seat and being adapted to receive said projections, a spring controlling the movements of a pair ofthe valve bodies in the cover, a hollow projection formed on said casing, communicating with said casing and having two countersunk openings to the outside, a double packing cone, seated in each of said openings, delivery and suction tubes having widened ends fitting into said openings onto said cone, said openings in said casing being provided with internal threads, and threaded sleeves engaged over said tubes in said openings for pressing the ends of the tubes against the cones and the cones onto the casing.

GUSTAV THOMAS. 

